As anyone with even a casual acquaintance with Aquinas's writings is
aware, it is in the Summa theologiae (ST) I, q. 2, a. 3 that he presents his
best-known formulation of argumentation for God's existence. A number of
the arguments from his earlier writings foreshadow most, if not all, of the
“five ways” of the Summa theologiae. These points of similarity notwithstanding, Thomas gives a personal and particular touch to each of the five ways
themselves. Because of the relatively later date of this treatment (ca. 1266–
1268), because of the apparently wider readership at which the Summa theologiae is aimed, and because of the comprehensive way in which the five
ways are fitted together, these arguments for God's existence have received
more attention from Thomas's students than any of his other efforts to
establish this point.
1

At the same time, it should be remembered that the amount of space
accorded to each of the five ways is relatively brief and that in certain instances, at least, familiarity with some of Thomas's most fundamental metaphysical options is presupposed by them.
2 Finally, the question has often been
raised concerning whether the five ways are intended by Thomas to form
one developing argument for God's existence, or five distinct and more or
less independent arguments. To put this in other terms, how are these five
proofs intended to fit together? Before making any attempt to answer this
question, however, it will first be necessary for us to consider each of them
in turn.

Question 2 of the First Part of the Summa theologiae is addressed to this
issue: Does God exist?
3 In a. 1 Thomas again rejects any claim that God's
existence is self-evident (per se notum) to us, even though he continues to
hold that the proposition “God exists” is self-evident in itself. Its predicate is
identical with its subject since God's essence is his act of being (esse). Because
we do not know of God what he is, that he exists is not known to us per

Print this page

While we understand printed pages are helpful to our users, this limitation is necessary
to help protect our publishers' copyrighted material and prevent its unlawful distribution.
We are sorry for any inconvenience.